Hemorheological changes in retinal vein occlusions

Some hemorheological factors were studied in 34 patients affected by retinal vein occlusion (RVO) and in 25 healthy control subjects. Whole blood viscosity, plasma viscosity, fibrinogen and hematocrit were increased in RVO patients compared with controls. Erythrocyte filterability was reduced in RVO patients compared with controls. However, when evaluating the type of capillaropathy at fluorescein angiography, blood viscosity and plasma viscosity were altered both in patients with and without evidence of capillary non-perfusion. Reduction of red cell filterability showed statistical significance only in patients with capillary non-perfusion. This finding suggests that reduced erythrocyte filterability might be a causal factor in the development of capillary non-perfusion in RVO patients.